Method and apparatus for treating continuous films



May 8, J. SHAW ET AL 1,958,211

METHOD AND APPARATUS FOR TREATING CONTINUOUS FILMS Original Filed y 21925 5 Sheets-Sheet 1 INVENTORS ,/ATT RNEYS May 8, 1934. J s w ET AL1,958,211

METHOD AND APPARATUS FOR TREATING CONTINUOUS FILMS O'riginai Filed y 25.1925 5 Sheets-Sheet 2 4 INVYENTORS %Ki'flwaMMM/f ATTO RNEYS J. SHAW ETAL 1,958,211

ATING CONTINUOUS FILMS May 8, 1934.

METHOD AND APPARATUS FOR THE Original Filed May 26, 1925 5 Sheets-Sheet3 0 ATTORNEYS J. SHAW El AL 1,958,211

METHUD AND APPARATUS FOR TREATING CONTINUOUS FILMS May 8, 1934.

Original Filed May 26, 1925 5 Sheets-Sheet {l May 8, 1934. HAW 5A,1,958,211

METHOD AND-APPARATUS FOR TREATING CONTINUOUS FILMS Original Filed May26, 1925 5 Sheets-Sheet 5 ITED STATES PATENT OFFICE METHOD AND APPARATUSFOR TREATING CONTINUOUS FILMS Joseph Shaw and John W. Berwick, New York,N. Y.

Application May 26, 1925, Serial No. 32,868 Renewed April 1, 1933 7Claims.

The present invention relates to the art of producing motion pictures.

The invention has for an object to provide an improved method andimproved apparatus for treating continuous films of the type used inproducing motion pictures in color and more particularly for treatingdouble coated films.

Projection positives for projecting motion pictures in natural colorsare produced by providing two series of images of diiferent colorselected value on opposite sides of a double coated film and then dyeingthe two series with suitable contrasting or complementary colors. Theproducing of such positives requires treatment of each side of the filmindependently and with different dyes.

The present invention has been developed more particularly to provide amethod and apparatus for dyeing a double coated film with difierentcolors and such an embodiment of the invention will be described forpurposes of illustrating the principles involved. The description isillustrative merely and is not to be construed as defining the limits ofthe invention.

Referring to the accompanying drawings form ing a part hereof,

Figure l is a side view of a portion of an illustrative apparatusconstructed in accordance with and embodying the principles of theinvention.

Figure 2 is a similar view in elevation of the remainder of theapparatus.

Figure 3 is a view in end elevation of the drying apparatus shown inFigure 2.

Figure 4 is a sectional View taken on the line 4-4 of Figure 1.

Figure 5 is a.detail view of one of the adjustable discharge pipes.

Figure 6 is a perspective View showing the construction of one of thetreating tanks.

Figure 7 is an end view of the same, a portion of the outer end wallbeing broken away.

Figure 8 is a detail view in front elevation of a portion of the dryingapparatus.

Figure 9 is a detail view in side elevation of the same.

Figures 10 and 11 are detail views of parts of the drying apparatusshown in Figures 8 and 9.

Figures 12 and 13 are detail views of the film feeding mechanism.

The apparatus shown in the drawings for the purpose of illustrating theinvention is arranged to provide for the continuous treatment of amotion picture film having emulsions on both sides thereof.

The apparatus is designed more particularly for dyeing a film which hasbeen developed but ob- .circuit and sound the alarm 14.

viously its use is not necessarily limited to this use. The film is fedslowly through the apparatus at a predetermined constant speed. Duringits travel it is successively treated with a bleaching solution toprepare it to receive dye, washed to remove the bleaching solution, thenwetted on both sides to prevent curling and thereafter dyed on one side,washed, dried, and wound on a suitable receiving reel. Provision is madefor controlling the extent of treatment as desired.

Referring more particularly to the structure shown a supply reel 5 asshown at the left in Figure l is mounted on the table 6 in position tosupport the film to be treated. The film 7 is fed from the supply reeland through the apparatus by means of sprocket wheels 25 and 45 andother feeding devices suitably positioned at spaced points in theapparatus. The film first passes beneath a movable roller 8 with whichis connected an automatic alarm device to cause an alarm in case thefilm breaks or when the end of the film is drawn from the reel 5. Asshown, a rod 10 is connected to one arm of the bell crank 11 supportingthe roller in such manner that as the roll drops, upon breaking of thefilm or reaching the end thereof, the rod will be projected between twocontacts 12, 12 to close an electric From the tension roller 8, the film7 passes over guide roller 15 and then down beneath a guide roller 16,forward under a guide roller 17 and along the surface of a series oftreating tanks 20 to 24. The film is first treated with a bleachingsolution in treating tank 20, and then washed as it passes over tanks 21to 24. Ordinarily, it is unnecessary 99 to vary the amount of time ofbleaching and only limited treatment is necessary. Accordingly, and asshown, only one tank is arranged to be supplied with this solution. Thefilm next is washed and then passes under a sprocket feed wheel 25, overa guide pulley 26 and down into a tank 27 Where it is immersed in waterto wet both sides thereof. The loop of the film which extends down intothe tank 27 is held under a slight tension by means of a Weighted guideroll 30 which serves not only to keep the loop of the film in properposit'on in the tank but also serves as a tension device to maintain thefilm under slight tension. The wetting of both sides of the filmsubstantially eliminates the tendency to curl or buckle and serves tokeep the film perfectly fiat during the further treatment. The advantageof thus wetting both sides of thefilm will be apparent when it isconsidered that otherwise the marked tendency to curl and occasionaltendency to buckle is substantially eliminated thus avoiding any loss offilm due to imperfect treatment. From the tank 27, the film passes overthe guide roll 31 and along the treating tanks 32 to 41 where the filmis first dyed and then washed. From these treating tanks the film passesbeneath and partially around a driving sprocket 45 through a dryingmechanism 46 to the air drying chamber 47. The drying device 46 may beof any desired type such as a blower or suction device. As the filmleaves the drying chamber it is wound upon a suitable receiving reel 50.

All of the treating tanks are similar except as to length and the numberand arrangement of the feed pipe connections. A description of one ofthe dye treating tanks will suflice for an understanding of all thesimilar tanks. One such is shown in Figures 6 and 7. This tank isprovided with guides 55 along the top edges of the side members tosupport the film as it is drawn thereover. The tank is provided withinner end walls 56 and outer end walls 57, the space between the outerand inner end walls serving to receive the overflow and being providedwith outlet pipes 58 to carry oif the water or treating solutions as itflows over the tops of the walls 56. Either dye or water'may be suppliedto the tank through suitable feed tubes. As shown, inverted T-shapedglass tubes 59 are each connected into the side of the treating tank.The upright member 60 of each tube is connected with a water feed pipeand the horizontal member is connected with a dye feed tube. Anyconnection which is not to be used may be corked.

Each outlet pipe 58 is provided with a rotatable extension 61 wherebythe discharge end can be turned to discharge into a tank or reservoir orto discharge into a waste trough.

In operation, the dye or water, is supplied constantly through one ormore of the inlet tubes to the tank proper between the end walls 56 andflows over these end walls in a manner to maintain the fluid incontactwith the lower surface of the film as it passes along the guides'55. The

height of the wall 56 is sufficient to maintain the water or othertreating fluid in contact with the film while preventing contact of suchend walls with the film. This avoids scratching of the film. The endwalls 56 are recessed at their center portions as indicated at 62 and attheir edges as indicated at 63. The recesses 62are desirable to avoidscratching of the film in case it bellies downward at the center. Therecesses 63 afford a more satisfactory circulation of the treating fluidin the tank.

The several treating tanks are suitably connected with fluid supplytanks whereby a constant flow therethrough can be maintained. Thebleaching solution is supplied to the treating tank 20 from a supplytank 65 from which it fiows to a supply pipe 66 whence it is fed throughfeeder tubes 67 to the treating tank 20. Suitable cocks 68 are providedin the connection to control the flow. The bleaching solution isdischarged from the treating tank 20 into a reservoir tank 69 from whichit is pumped by means of a centrifugal pump 70 back to the supply tank65 for re-use.

A water supply is maintained in tank 71, the level of water in which isalways maintained at a predetermined level by means of an automaticfloat valve '72. The head of water in the system is thus maintainedconstant insuring constant flow. Connected to the supply tank is ahorizontal supply pipe 73 extending horizontally above all of thetreating tanks. Suitable connections from this water supply pipe to allof the treating tanks is made by means of feed tubes '74 having cocks'75 to control the fiow of water.

Circulation of water is maintained in the wetting tank 27 by means of aconnection '76 with the water supply and an overflow 77.

A suitable number of treating tanks 32, 33, etc. are supplied with dyefrom the dye supply tank 78 and supply pipe 79 to dye the under surfaceof the film to the desired extent. The tanks not in use for dyeing aresupplied with water from the water supply pipe 73 and the connectingtubes so that when the film reaches the sprocket feed wheel 45 at theendof the series of tanks it will have been thoroughly washed of allsuperfluous dye. The film is then ready to be dried.

The dye used for treating the film in the tanks 32, 33, etc. isdischarged into the reservoir tank 80 from which it is pumped by meansof a centrifugal pump back to the reservoir 78 for re-use. The waterused in the other tanks, however, is discharged into the waste trough76.

Drying of the film is accomplished by removing the free water from bothsurfaces thereof by means of air suction devices and then exposing toair in a drying chamber. The suction dryer is better shown in Figure 8.In Figure 2 the suction mechanism is shown in front elevation and inFigure 8 it is shown in rear elevation. This mechanism comprises meansfor flexing the film in opposite directions and suction devicesadjustable to position closely adjacent and extending transversely ofthe film at points where it is flexed. In the particular constructionshown, the flexing or guiding means consists of film guide rollers 83and 84 together with guide rollers 85 engaging the opposite edges of thefihn to properly position it on the first roller 84. By thus flexing thefilm it may be maintained in a fixed position as, it passes the suctiondevices 86, 8'7, one of which is shown in detail in Figures 10 and 11.The suction is maintained in the suction pipes 88 and 89 by means of asuitable pump or fan 89A as indicated in Figure 2. The suction member 86is mounted on the pipe 88 to permit a limited pivotal movement towardand from the film. This member is provided with a nozzle slot 90arranged to lie adjacent the film as it passes over the guide roller 84,the slot being of a length to extend substantially the full width of thefilm. The position of the suction member 86 relative to the film can beadjusted by means of a stop screw 91 hearing against a fixed pin 92. Theconstruction of the suction member 87 mounted on pipe 89 issubstantially the same as that of the suction member 86 but a spring 94is provided to yieldably hold the suction nozzle toward the film. It isunnecessary to use a similar spring in connection with the suctionmember 86 for the reason that gravity will sufliciently hold this nozzlein place.

From the suction drying devices the film passes over the guide wheelsone or both of which may be frictionally or positively driven into thedrying chamber.

The drying chamber is best shown in Figures 2 and 3 and consists of arelatively narrow chamber 47 together with guide spools over which thefilm is passed during its travel therethrough.

Two series of film guide spools 95, 96 are loosely mounted uponhorizontal shafts 9'7, 98 at the top and bottom of the drying chamber.The film enters the drying chamber over the guide spools 100, 101,passes downwardly around an idle spool 101A, then up to the first of theloosely mounted spools on the upper horizontal shaft. The belt is thenpassed back and forth over the spools on the lower and upper shafts.Both the upper and lower shafts may be positively driven if desired butordinarily it is sufficient if as shown the upper shaft is driven. Bythis arrangement there is a certain yieldable driving force exerted oneach spool and the film may be kept in substantially taut condition atall points in the drying chamber without danger of excessive tensionbeing exerted on any part thereof.

In the particular arrangement shown the lower central guide spool 103 ismounted upon a bracket 104 somewhat above the level of the lower shaftto avoid interference with a supporting bracket of said lower shaft.

It is found that the outwardly presented side of the film tends to drymore rapidly than the inwardly presented side. For this reason it ispreferable to twist the film at certain points as indicated at 105, 106during its passage through the chamber so that first one side and thenthe other will be presented outwardly to the drying air. By thisarrangement the two sides of the film dry in about the same time and thetendency of the film to curl is substantially reduced. At the deliveryend of the chamber the film passes over a sprocket wheel 109 which isyieldably driven as by means of a spring tension belt 110. The reel 50on which the film is wound as it is delivered from the drying chamber isalso frictionally driven as by means of a spring friction belt 111.

After one surface of the film has been treated with a dye of one colorthe other surface may be treated. If it is to be treated with a seconddye in a similar apparatus including a washing tank such as the tank 2'7in which the film is immersed, it is preferable to first dry'the filmbefore the second treatment in order that the dye of the first treatmentmay not wash out in the washing tank.

The sprocket wheel 45 is driven from a main power shaft indicated inFigure 2 as by means of a vertical shaft and suitable connectinggearing.

The sprocket wheel 25, Figure l, is driven by sim ilar drivingconnections, not shown.

The method of treatment although in fact independent of the particularapparatus shown, has been sufiiciently described in connection with thedescription and explanation of the operation of the apparatus shown. Itwill be particularly noted that the film is wet on both sides beforebeing I passed over the tanks containing the dyeing fiuid.

We claim:

1. A treating tank comprising parallel guides for supporting a movingfilm and having an inlet, the end wall of said tank having its upperedge recessed adjacent the sides of the tank and centrally recessed toconform to the curve of a sagging film, the whole end wall being of aheight less than that of the guides whereby the film passing along saidguides willnot contact with the end wall. and. whereby the liquidsupplied to said tank will constantly overflow said end wall and willcontact with the film carried by said guides Ehroughout the greaterportion of the area of the ank.

2. A treating tank of the character described having longitudinal filmguides and end walls the tops of which lie slightly below the filmguides, said end walls being recessed at their ends and centerssubstantially as and for the purpose described.

3. The method of treating a double-coated -i'no tion picture film whichcomprises successively treating one side of the dry film with ableaching solution, washing the treated side, wetting the opposite sideand then dyeing the first treated side with a color dye.

4. The method of treating a motion picture film which comprisessuccessively treating one side of the dry film with a bleachingsolution, washing the treated side, wetting the opposite side and thendyeing only the first treated side with a color dye, and drying saidfilm by first removing excess moisture by means of a suction nozzle andthen drying 1n air.

5. The method of treating a motion picture film which comprisessuccessively treating one side of the film with a bleaching solution,washing the treated side, wetting the opposite side and then dyeing onlythe first treated side with a color dye,

removing the excess moisture from said film by means of a current of airand then drying in air.

6. The method of treating a continuous film which comprises treating theunder-surface only with a bleaching solution, wetting the upper-surfaceof said film to prevent curvature and thereafter treating theunder-surface only with a dye, removing excess moisture by means of asuction device from both surfaces of the film and drying said film.

7. In apparatus for treating double coated motion picture film, incombination means for treating the under surface only with a liquid,means for wetting the upper surface of said film to prevent curvatureand means for thereafter treating the under surface only with a dye,together with means for removing the excess moisture from both surfacesand drying said film.

JOSEPH SHAW. JOHN W. BERWICK.

